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Catalytic conversion of environmentally hazardous chemicals to benign compounds.

机译：将对环境有害的化学品催化转化为良性化合物。

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There is an increasing demand for technology that can be used to convert environmentally hazardous chemicals into benign and useful compounds. Generation of these new technologies relies on a fundamental understanding of the nature of catalytic activity. This thesis provides such an understanding of the selective conversion of two major classes of compounds (Chlorocarbons and Automotive emissions) to more environmentally benign alternatives.; The research carried out on the conversion of 1,2-dichloroethane to ethylene over a bimetallic Pt-Cu catalyst is presented in Chapter 3. It was found that for monometallic Pt catalyst and for those with Cu/Pt atomic ratio 1, the reaction products were mainly ethane and monochloroethane. However, as the Cu/Pt ratio was increased from 1 to 18, the selectivity towards ethylene increased to almost 90%. Monometallic Cu exhibited 100% selectivity towards ethylene but its activity was 2 orders of magnitude lower than the bimetallic catalysts. A molecular level picture involving the effect of equilibration of bimetallic particles during the reaction on the ethylene selectivity has been developed.; Bimetallic Pt-Cu catalysts supported on silica were studied using infrared spectroscopy. Infrared investigations of CO adsorption indicate that Pt and Cu form bimetallic particles during the catalyst pretreatment and that besides a dilution effect of Cu on Pt ensembles, Cu alters the electronic properties of Pt atoms. In this context, the cause of increased selectivity and activity of the bimetallic catalysts when compared to the monometallic catalysts is discussed in detail in Chapter 4.; Automotive exhaust treatment has been a widely researched area in environmental catalysis. Of particular interest is the development of sulfur tolerant catalysts. Two catalysts Pd/CeO2 and Pd/CeO2-ZrO2 were studied for the NO + O2 + CO + C3H6 reaction both in the presence and absence of SO2 and under different feed-stream conditions. Although Pd/CeO2 was active for the conversion of NO x, CO and C3H6 in the absence of SO2, its activity was affected by the presence of 20 ppm of SO2. Addition of ZrO2 increased the stability and activity of the catalyst both under steady reactant stream and cyclic conditions. These results are discussed in detail in Chapter 5.
机译：对可用于将对环境有害的化学品转化为良性和有用化合物的技术的需求不断增长。这些新技术的产生依赖于对催化活性本质的基本理解。本文对两种主要化合物（碳氢化合物和汽车排放物）选择性转化为对环境无害的替代品提供了这样的理解。第三章介绍了在双金属Pt-Cu催化剂上1,2-二氯乙烷转化为乙烯的研究。发现对于单金属Pt催化剂和Cu / Pt原子比<1的催化剂，反应产品主要是乙烷和一氯乙烷。但是，随着Cu / Pt比从1增加到18，对乙烯的选择性增加到几乎90％。单金属铜对乙烯具有100％的选择性，但其活性比双金属催化剂低2个数量级。已经开发出涉及反应期间双金属颗粒平衡对乙烯选择性的影响的分子水平图。使用红外光谱研究了负载在二氧化硅上的双金属Pt-Cu催化剂。红外吸附研究表明，Pt和Cu在催化剂预处理过程中会形成双金属颗粒，除了Cu对Pt团簇的稀释作用外，Cu还会改变Pt原子的电子性质。在这种情况下，与单金属催化剂相比，双金属催化剂的选择性和活性增加的原因将在第四章中详细讨论。汽车尾气处理已成为环境催化领域中被广泛研究的领域。特别令人感兴趣的是耐硫催化剂的开发。研究了两种催化剂Pd / CeO2和Pd / CeO2-ZrO2在有无SO2以及不同进料流条件下的NO + O2 + CO + C3H6反应。尽管在不存在SO2的情况下Pd / CeO2对NOx，CO和C3H6的转化具有活性，但其活性受20 ppm SO2的影响。 ZrO 2的添加在稳定的反应物流和循环条件下均增加了催化剂的稳定性和活性。这些结果将在第5章中详细讨论。

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